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MIT and NASA Designing Silent Aircraft
Iddo Genuth writes "Researchers at the Massachusetts Institute of Technology Department of Aeronautics and Astronautics recently won a contract from the National Aeronautics and Space Administration to design quieter, more energy efficient, and more environmentally friendly commercial airplanes. The two-million-dollar contract from NASA is just an initial step in bringing green technologies to the sky."
Only 2 million...? For a new plane design?
Disclaimer: I am not god.
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But we can be treated equal.
Don't expect your airport-side property values to rise just yet.
Despite strides in cleaner and quieter engine technology, there will still be many older planes flying without the retrofits.
Certain airports have restrictions on takeoff hours to quell the noise during bedtime hours but note that the same airports still must allow landings at all hours!
I don't see how efficiency can go down because noise and efficiency go hand in hand. Noise is caused by air turbulence, reducing air turbulence will increase efficiency.
Having said that, two million is a drop in the ocean for this sort of thing. How come the USA can spend trillions bailing out stupid bankers but only has a couple of million for this sort of thing?
No sig today...
I'd put many smaller, distributed brushless electric-motors all along the wing, especially towards the wingtips.
In order to help increase lift based on pressure (active pressure differences), I'd place the propeller centers below the wing, rather than above the wing.
To counteract some of the loss of lift from wingtip vortex pressure losses, I'd make the propellers spin with the bottoms moving towards the fusilage.
In order to reduce explosion risk, I'd use Lithium-ion phosphate batteries.
I'd probably also have to have a very long aspect ratio for the wing, so the plane wouldn't be flying all that fast.
But it could be done, and be economical (in terms of cost per flight hour, cost per mile) too. It wouldn't be economical for someone who wanted to go from here to there fast.
So if you were an automobile executive who wanted to declare that your company was about to go bankrupt unless you got a few spare billion (and then declare that bankruptcy is not an option if you don't get it), you'd have to use a lear jet instead, preferably retrofitted with a zillion pulse jets. But they make a tad more noise, and use a tad more fuel.
Different economic situations require different answers, I guess.
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Theres a whoooole lot of people that said never. As in; we were never supposed to fly, never supposed to break the sound barrier, never supposed to get to space, etc.
Noone said it would be easy, or that they have an idea how to do it. but thats why we do these studies.
Luckily people that don't like to say "never" work at NASA.
There's nothing Intelligent about Intelligent Design.
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hehehe. My dad was air force. Ever heard a b-47 with a JATO pac take off? Makes the 727 a whisper jet. Even the DC8's (which were much noisier than 727 or 707). What was cool was to see the practiced take off for a squadron. something like 10-15 seconds apart. pitch black. My understanding is that only the lead could see anything. If an accident occurred on take off, my understanding is that it would be SEVERAL aircrafts collosion before it was realized that a problem had occurred.
I prefer the "u" in honour as it seems to be missing these days.
Also, don't forget the military aspect of this - F4 Phantoms were intimidating, but they certainly wouldn't sneak up on anyone, even if the person was deaf they could feel an F4 coming. F16s are a huge improvement, noise wise. I've never heard a stealth fighter in person, but I assume their noise signature could be reduced too. A fighter jet capable of silent approach and supersonic response speeds would have plenty of applications.
I disagree. The Phantom can most definitely sneak up on you from behind. I took pictures of it at an airshow recently. Taking a picture and immediately plugging my ears afterwards was quite a trick, since it was flying very low and I forgot earplugs. You see it coming and then at about 30 yards hissssBOOM! I'd call that sneaking up. You don't have time to do anything but dive. There was also an F22 on display, but nobody was considerate enough to fly it. :(
The government can't save you.
If they can reduce the sound output to where the noise from a jet at cruising altitude is less than normal ambient noise in a suburban neighborhood, that would be a big accomplishment. I doubt they'll get it down to where you can't hear them while standing in a quiet field away from air-conditioners noise of passing cars - but they can try...
Attend a large (or military) airshow sometime. The US's newest military transport, the C-14 Globemaster, is absolutely eerie. A huge, lumbering aircraft that is close to silent for it's size.
Aah, change is good. -- Rafiki
Yeah, but it ain't easy. -- Simba
FedEx used to throttle up for climb out with their engines pointed at my house, the windows would rattle for 2-3 minutes. How do I know it was Fed-Ex? because I complained to the airport, they took the information and sent me a radar track with an ID of the aircraft that matched my complaint time and location. I asked if they were going to do anything about these jets that are making a mockery of the intended flight path (climb out was intended to be over water, but being a cargo jet, they would pull it hard left as soon as they passed the "gate"), answer was that they would continue to track the planes and please keep the complaints coming, because it justifies his job as complaint tracker (translation: no,...or, are you high man? we can't do anything about how the pilots chose to fly their planes - it's called air traffic control, but it's really more like a polite request).